You got give more details:
What networking are you using vDS or NSXv?
If you are using DVS, have you created the provider networks? (scrn shot of the "Horizon --> network topology" view from the tenant would be useful)
Create a new instance. Paste the UUID of that instance along with the viogetlogs (its deprecated but should work... with sudo on OMS)
If you are not using a syslog server please do so. There are lot of logs and it will save you a lot of time to analyze these errors.
arvind